Abstract
A linear stability analysis has been presented for the vortex instability of free convection boundary layer flow in a saturated porous medium adjacent to an inclined non-isothermal heated plate. The variation of permeability in the vicinity of the solid boundary has been approximated by an exponential function. Velocity and temperature profiles as well as dimensionless local heat transfer rates in the form of the Nusselt number for the base flow are presented for the uniform permeability (UP) and variable permeability (VP) cases. The critical Rayleigh numbers and the associated wave numbers are obtained for both UP and VP cases. It is found that the variable permeability effect tends to augment the heat transfer rate and destabilize the flow to the vortex mode of disturbance.